Studies on the Interactions of Paracetamol in Water and Binary Solvent Mixtures at T = (298.15–313.15) K: Viscometric and Surface Tension Approach

Abstract

Temperature, concentration, and solvent conditions have consequences on the formation and dissolution of the drug. Viscometric measurements of paracetamol solutions of different concentrations in 5, 10, and 15% methanol have been made at 298.15, 303.15, 308.15, and 313.15K. Surface tension values (γ) of the solutions were obtained experimentally by using a stalagmometer as well as were derived from the ultrasonic velocity (U) and density (d) values at 298.15 K. The surface tension data have been analyzed using the Gibbs equation to evaluate surface excess (Γ_2). The surface tension and surface excess data obtained by the two different methods are well in accordance. The viscosity (ɳ) data were used to calculate relative viscosity (ɳ_(r ) ), Falkenhagen coefficients (A_(F )), Jone-Dole’s coefficients (B_(J ) ) and chemical potential (μ). The obtained data have been analyzed based on the Jones-Dole equation to know the molecular interactions.